Support for rendering/redacting multiple documents

This commit changes the way certain documents are rendered (currently
only Notes) and how documents are redacted. Previously both rendering
and redacting would run on a per document basis. The result of this was
that for every document we'd have to run countless queries just to
figure out if we could display a set of links or not.

This commit changes things around so that redacting Markdown documents
is no longer tied into the html-pipeline Gem. This in turn allows it to
redact multiple documents in a single pass, thus reducing the number of
queries needed.

In turn rendering issue/merge request notes has been adjusted to take
advantage of this new setup. Instead of rendering Markdown somewhere
deep down in a view the Markdown is rendered and redacted in the
controller (taking the current user and all that into account). This has
been done in such a way that the "markdown()" helper method can still be
used on its own.

This particular commit also paves the way for caching rendered HTML on
object level. Right now there's an accessor method Note#note_html which
is used for setting/getting the rendered HTML. Once we cache HTML on row
level we can simply change this field to be a column and call a "save"
whenever needed and we're pretty much done.

1 files changed, 120 insertions, 0 deletions

diff --git a/spec/lib/banzai/object_renderer_spec.rb b/spec/lib/banzai/object_renderer_spec.rb
new file mode 100644
index 00000000000..44256b32bdc
--- /dev/null
+++ b/spec/lib/banzai/object_renderer_spec.rb
@@ -0,0 +1,120 @@
+require 'spec_helper'
+
+describe Banzai::ObjectRenderer do
+  let(:project) { create(:empty_project) }
+  let(:user) { project.owner }
+
+  describe '#render' do
+    it 'renders and redacts an Array of objects' do
+      renderer = described_class.new(project, user)
+      object = double(:object, note: 'hello', note_html: nil)
+
+      expect(renderer).to receive(:render_objects).with([object], :note).
+        and_call_original
+
+      expect(renderer).to receive(:redact_documents).
+        with(an_instance_of(Array)).
+        and_call_original
+
+      expect(object).to receive(:note_html=).with('<p>hello</p>')
+
+      renderer.render([object], :note)
+    end
+  end
+
+  describe '#render_objects' do
+    it 'renders an Array of objects' do
+      object = double(:object, note: 'hello')
+      renderer = described_class.new(project, user)
+
+      expect(renderer).to receive(:render_attribute).with(object, :note).
+        and_call_original
+
+      rendered = renderer.render_objects([object], :note)
+
+      expect(rendered).to be_an_instance_of(Array)
+      expect(rendered[0]).to be_an_instance_of(Nokogiri::HTML::DocumentFragment)
+    end
+  end
+
+  describe '#redact_documents' do
+    it 'redacts a set of documents and returns them as an Array of Strings' do
+      doc = Nokogiri::HTML.fragment('<p>hello</p>')
+      renderer = described_class.new(project, user)
+
+      expect_any_instance_of(Banzai::Redactor).to receive(:redact).
+        with([doc]).
+        and_call_original
+
+      redacted = renderer.redact_documents([doc])
+
+      expect(redacted).to eq(['<p>hello</p>'])
+    end
+  end
+
+  describe '#context_for' do
+    let(:object) { double(:object, note: 'hello') }
+    let(:renderer) { described_class.new(project, user) }
+
+    it 'returns a Hash' do
+      expect(renderer.context_for(object, :note)).to be_an_instance_of(Hash)
+    end
+
+    it 'includes the cache key' do
+      context = renderer.context_for(object, :note)
+
+      expect(context[:cache_key]).to eq([object, :note])
+    end
+
+    context 'when the object responds to "author"' do
+      it 'includes the author in the context' do
+        expect(object).to receive(:author).and_return('Alice')
+
+        context = renderer.context_for(object, :note)
+
+        expect(context[:author]).to eq('Alice')
+      end
+    end
+
+    context 'when the object does not respond to "author"' do
+      it 'does not include the author in the context' do
+        context = renderer.context_for(object, :note)
+
+        expect(context.key?(:author)).to eq(false)
+      end
+    end
+  end
+
+  describe '#render_attribute' do
+    it 'renders the attribute of an object' do
+      object = double(:doc, note: 'hello')
+      renderer = described_class.new(project, user, pipeline: :note)
+      doc = renderer.render_attribute(object, :note)
+
+      expect(doc).to be_an_instance_of(Nokogiri::HTML::DocumentFragment)
+      expect(doc.to_html).to eq('<p>hello</p>')
+    end
+  end
+
+  describe '#base_context' do
+    let(:context) do
+      described_class.new(project, user, pipeline: :note).base_context
+    end
+
+    it 'returns a Hash' do
+      expect(context).to be_an_instance_of(Hash)
+    end
+
+    it 'includes the custom attributes' do
+      expect(context[:pipeline]).to eq(:note)
+    end
+
+    it 'includes the current user' do
+      expect(context[:current_user]).to eq(user)
+    end
+
+    it 'includes the current project' do
+      expect(context[:project]).to eq(project)
+    end
+  end
+end